The present invention relates generally to encoder systems used for tracking movement of mechanical structures and, more particularly, to an analog encoder control system and related method which facilitates achieving more desirable encoder output signals.
Presently known analog encoder systems are often expensive due to the nature of the design, particularly due to the cost in manufacturing an encoder which will produce ideal analog output signals. Less expensive analog encoder systems, such as those using an encoder mask which is external to the photo sensors, may produce distorted analog output signals. For example, where the ideal analog output signals are triangle waves, less expensive encoder systems may instead produce more sinusoidal output signals which lack linearity throughout the entire signal.
Different encoder channels typically have different output levels for the same light intensity due to differences in components on the photo sensor side of the encoder. In the past, in order to attempt to produce encoder signals having matching characteristics, gain control circuitry has been used on the photo sensor side of the encoder. However, such gain control circuitry can be expensive.
It would be advantageous to provide an encoder system in which the cost and complexity of the gain control circuitry on the photo sensor side of the encoder is reduced or eliminated.
In one aspect, a method for tracking movement of a structure using first and second encoder output signals involves: (a) monitoring only one of the first and second encoder output signals at a time; (b) during monitoring of the first encoder output signal, energizing an encoder light element at a first energization level; and (c) during monitoring of the second encoder output signal, energizing the encoder light element at a second energization level which is different than the first energization level.
In another aspect, a method for tracking movement of a structure using first and second encoder output signals involves: (a) monitoring only one of the first and second encoder output signals at a time; (b) storing first and second energization levels for use in energizing an encoder light element; (c) during monitoring of the first encoder output signal, energizing the encoder light element according to the first stored energization level; and (d) during monitoring of the second encoder output signal, energizing the encoder light element according to the second stored energization level.
In yet another aspect, a method is provided for controlling an encoder in a position tracking system in which first and second encoder output signals are produced by an encoder and only one of the first and second encoder output signals is monitored at any given time. The method involves: (a) during monitoring of the first encoder output signal, energizing an encoder light element at a first energization level; and (b) during monitoring of the second encoder output signal, energizing the encoder light element at a second energization level which is different than the first energization level.